Schedule Your Appointment

9 Common Reasons Why Your Check Engine Light Is On

Engine Light

The check engine light is one of the most annoying warning lights that can appear on your car’s dashboard. It is an indicator that something is wrong with the vehicle, and it needs to be checked. Several things could cause the check engine light to turn on, and in this article, we will explore the nine common reasons why that may be the case.

1. Faulty Oxygen Sensor

The oxygen sensor controls the air/fuel ratio based on readings of oxygen levels in the exhaust. In the event that it is defective, it may result in a decrease in fuel efficiency as well as an increase in emissions.

2. Loose or Damaged Gas Cap

The gas cap prevents fuel from evaporating by keeping the fuel tank at the proper pressure. It is possible for it to trigger the malfunction indicator light to turn on if it is damaged or loose.

3. Malfunctioning Catalytic Converter

The catalytic converter’s job is to transform potentially dangerous gasses into much lower-impact pollutants. If it’s malfunctioning, the car might not pass an emissions test, and the check engine light might turn on.

4. Bad Spark Plugs or Ignition Coils

The engine’s fuel is ignited by spark plugs and ignition coils. If any of these components aren’t operating as they should, the engine could misfire, and the light that indicates a problem with the engine would turn on.

5. Failed Mass Airflow Sensor

The engine’s computer receives data from the mass airflow sensor, which monitors the volume of air entering the machine. If it breaks, your gas mileage will suffer, and you’ll be responsible for more pollution. The engine may also stall or hesitate as a result.

6. Faulty EGR Valve

A part of the exhaust gas is brought back into the engine via the EGR valve located in the exhaust system. It is possible for it to trigger the malfunction indicator light that is located on the instrument cluster. A sulfurous odor may also be produced, in addition to the possibility that the engine would stall or hesitate.

7. Bad Thermostat

The temperature of the engine can be controlled by the thermostat, which does so by allowing and stopping the flow of coolant. In the event that it is not operating as it should, the engine may get too hot, which will cause the check engine light to turn on. Driving with a defective thermostat might significantly damage the vehicle’s engine.

8. Failed Ignition Switch

The engine can be started and stopped using the ignition switch. If it is not functioning properly, the engine might not start at all, or it might cut out while you are driving. That said, the failure of the ignition switch is another potential reason for the check engine light to illuminate.

9. Low Battery Voltage

The starting motor and other electrical components in the vehicle receive their power from the car’s battery. A low voltage in the battery can trigger the warning light for the engine. It is also possible for it to cause the car’s electrical system to malfunction, which will result in the illumination of additional warning lights.


The check engine light can turn on for several reasons, and getting it checked as soon as possible is essential. Ignoring the check engine light can lead to more significant problems down the road, and it can also cause damage to other engine components. If your check engine light is on, take your car to a qualified mechanic to diagnose and fix the problem.

If your American or Japanese vehicle is in need of an engine mechanic in Culver City, look no further than our services here at Automed Car Care. Whether your car needs brake repairs, an oil change, battery repairs, or another type of service, count on our mechanics to get the job done to your satisfaction. Visit our nearest branch today and let us tend to your car engine in no time!

Schedule Auto Service

Your Automotive Repair & Maintenance Service Specialist

***Please note that the date and time you requested may not be available. We will contact you to confirm your actual appointment details.